To reproduce:

Go to Playground: https://lesscss.org/less-preview/#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

Change

// Take blue and make it a bit darker
background: oklch(from #0000FF calc(l - 0.1) c h); 

to

// Take blue and make it a bit lighter
background: oklch(from #0000FF calc(l + 0.1) c h);

Current behavior:

Error: Could not parse call arguments or missing ')'

Expected behavior:

Parse color manipulations properly

Environment information:

• less version: 4.3.0